A switch is a break in an electric circuit. It works by opening and closing a gap in the circuit. When a gap is introduced, the circuit is broken and the electric current cannot flow.

A material that does not allow an electric current to flow through it is called an electrical insulator. Plastic, rubber and other non-metal materials are insulators.

An electrical conductor is a material that allows an electric current to flow through it. Most metals conduct electricity.

Electricity does not simply appear in our homes. It is made (generated). It can be made in power stations burning fossil fuels (coal), using a nuclear reaction or by using the wind, sun (solar power) or water (hydro-electric power).

Mains Electricity

The electricity available from a plug socket is called mains electricity. It supplies 240 volts.

Volts

Electrical power is measured in volts (v).

Series Circuit

A circuit where all the components are connected to each other so the current has to flow through all of them before it returns to the battery or power source.

Parallel Circuit

A circuit where the components are connected together in such a way that the electric current has a number of different routes back to the battery or power source.